DE3831579A1 - PHOTO-CONDUCTIVE COMPOSITION AND ELECTROPHOTOGRAPHIC PHOTO RECEPTOR USING THIS - Google Patents

Description

The present invention relates to a photoconductive composition, which contains a new bisazo compound, and an electrophotographic photoreceptor with a light sensitive electrophotographic layer, which the Bis contains azo compound.

The light conduction process in an electrophotographic photoreceptor involves the following stages:
(1) generation of an electric charge by exposure; and
(2) transportation of electric charge.

An example in which the two steps (1) and (2) with of a substance is a photosensitive one Selenium plate. As an example for the separate implementation stages (1) and (2) in different compounds a combination, the amorphous selenium and poly-N-vinylcarbazole includes, known. The procedure in which steps (1) and (2) performed separately with different substances has the advantage that there is a choice of to use materials available in electrophotographic photoreceptors enlarged and also the electrophotographic Properties such as B. Sensitivity and acceptable Potential that improves electrophotographic photoreceptors. It can also contain substances that contribute to formation of coating films on the photoreceptors preferred be selected from a wide range.

As already described in US Pat. No. 2,297,691, in electrophotography uses a photoconductive material, which has a substance that isolates in the dark acts and their electrical resistance depending on the imagewise exposure thereof varies, plotted on  a layer support. In general, the photographic First processed material so that after dark Adaption has a uniform surface charge. Thereupon the material is exposed to a light irradiation pattern exposed imagewise, which causes the surface charge corresponding to the relative energy, those in the different parts of the light irradiation pattern is included, is reduced. The surface charge or that latent electrostatic image that is on the layer with the photoconductive substance (photosensitive electrophotographic Layer) remains, then becomes a visible Image converted after the surface with an appropriate one Substance that can recognize charges and make them visible, d. H. a toner that has been brought into contact.

The toner is in an insulating liquid or dry Contain carrier and in both cases it can correspond to the charge pattern formed on the surface of the photosensitive electrophotographic layer applied will. The visualizing substance (toner) so on the Image surface can be applied by conventional means, such as B. heat, pressure or solvent vapor. The latent electrostatic image can be transferred to a second Substrates (e.g. paper or a film) can be transferred. This can be done in the same way on the second substrate transferred latent electrostatic image developed on it will. Electrophotography is one of the image-forming ones Processes in which any desired images according to the processes mentioned above are formed.

Such electrophotography are fundamental Properties that the electrophotographic photoreceptors must have, e.g. B. the following: (1) you can in Darks are charged to an appropriate potential; (2) they hardly lose any charge in the dark; and (3) after irradiation with light they can release the charge quickly.  

The above-mentioned inorganic substances, which have so far been described in electrophotography have not only been used different advantages, but of course also different Disadvantage. For example, selenium can currently frequently used, the conditions mentioned above (1) to (3) satisfactorily, but manufacture is difficult and complicated and the manufacturing cost are high. In addition, the manufacturing process not flexible enough and the electrophotographic photoreceptor can hardly be deformed into a band-shaped product. Furthermore, you have to handle the electrophotographic Take great care because the photoreceptor he is sensitive to heat and mechanical shock. Consequently selenium has several disadvantages. Cadmium sulfide and Zinc oxide are used as electrophotographic photoreceptors used after being dispersed in a resin as a binder have been. These electrophotographic photoreceptors but show in terms of smoothness, hardness, tensile strength and Abrasion resistance mechanical defects and therefore they can not be used repeatedly without further ado.

Recently, electrophotographic photoreceptors, which have different organic substances been made to overcome the disadvantages of inorganic substances and some have also been put into practice. For example, there are electrophotographic photoreceptors which include poly-N-vinylcarbazole and 2,4,7-trinitrofluoren-9-one (U.S. Patent 3,484,237); electrophotographic photoreceptors, with poly-N- sensitized with a pyryllium salt dye vinyl carbazole (JP-B-48-25 658); (The term "JP-B" means Examined Japanese Patent Application); and electrophotographic Photoreceptors, the main component of which is a eutectic Having a complex comprising a dye and a resin; (JP-A-47-10 735); the term "JP-A" means unchecked, published Japanese patent applications).  

In addition, electrophotographic have recently been used Photoreceptors have been widely studied, the one Contain azo pigment as the main component and various Proposals have been made, e.g. B. are described in US Pat. Nos. 38 98 084, 46 18 672, 43 96 696, 43 56 243, 47 43 523, 46 66 810, 44 36 800, 44 39 506, 44 47 513, 45 98 033, 45 68 623, 45 33 613, 46 19 881 and 47 02 982.

The organic electrophotographic photoreceptors are the inorganic electrophotographic mentioned above Photoreceptors are superior because the former are somewhat improved mechanical Have properties and improved flexibility. The organic electrophotographic photoreceptors but are generally sensitive to light unsatisfactory when used many times and are therefore unsuitable for repeated use. Thus, the above-mentioned organic substances the one placed on electrophotographic photoreceptors Requirements are not always satisfactory suffice.

An object of the present invention is to provide one new electrophotographic photoreceptor that is both high Has sensitivity as well as high durability.

Another object of the present invention is to provide of a new electrophotographic photoreceptor, the Sensitivity to light even after repeated use hardly diminished.

Yet another object of the present invention is that Creation of a new photoconductive composition, which in various electrophotographic photoreceptors can be.

To achieve the above objects, the present invention provides a photoconductive composition that has a new bis  azo compound (bisazo pigment) comprised by the following Formula (I) is represented, and also represents an electro photographic photoreceptor with a photosensitive electrophotographic layer containing the bisazo compound contains, available.

In particular, the present invention provides a photoconductive Composition characterized in that it comprises at least one bisazo compound which is characterized by the the following formula (I) is represented:

in which Z for

stands where
R⁶ represents a hydrogen atom or a substituted or unsubstituted alkyl or aryl group;
A for

stands;
B₁ and B₂, which may be the same or different, independently represent hydrogen, halogen or a substituted or unsubstituted alkyl or alkoxy group;
X represents a group which forms a substituted or unsubstituted aromatic or heterocyclic ring by condensation with the benzene ring in the above formula having a hydroxy group and a group Y on the ring;
Y for

stands;
R¹ represents a substituted or unsubstituted alkyl or phenyl group;
R² represents hydrogen, an alkyl group, a carbamoyl group, a carboxyl group, an alkoxycarbonyl group, an aryl oxycarbonyl group or a substituted or unsubstituted amino group;
R³ represents an alkyl group, an aromatic group or a heteroaromatic group, which groups may be substituted or unsubstituted;
R⁴ and R⁵ independently of one another are hydrogen, an alkyl group, an aromatic group or a heteroaromatic group, these groups being able to be substituted or unsubstituted, with the proviso that R⁴ and R⁵ cannot both be hydrogen at the same time and that if Y

is R⁵ cannot be hydrogen,
W represents a divalent group that forms an aromatic hydrocarbon ring or represents a divalent group that forms a hetero ring that contains one or more nitrogen atoms in the ring, which rings may be unsubstituted or substituted; and
L represents a substituted or unsubstituted alkyl or aryl group.

The present invention further provides an electrophotographic Photoreceptor available on one electrically conductive layer carrier has a layer, which a charge carrier transporting connection and a Contains charge-generating compound, or a layer, which contains a charge transporting connection and a layer containing a charge generation compound contains, wherein the charge carrier-producing connection is a bisazo compound of formula (I) described above.

The bisazo compounds represented by the above formula (I) are described in detail below. Z stands for

where R⁶ is hydrogen or an alkyl or aryl group with Represents 1 to 18 carbon atoms.

If R⁶ represents an unsubstituted alkyl group, specific ones are Examples include methyl, ethyl, propyl, butyl, pentyl, Hexyl, dodecyl, octadecyl, isopropyl, isobutyl, isohexyl, Neopentyl and tert-butyl.

If R⁶ represents a substituted alkyl group, the Substituents e.g. B. hydroxy groups, alkoxy groups with 1 to 18 carbon atoms, cyano groups, alkylamino groups with 1 up to 18 carbon atoms, dialkylamino groups with 2 alkyl groups, each of which has 1 to 18 carbon atoms, halogen atoms and aryl groups having 6 to 15 carbon atoms. Examples of substituted alkyl groups are hydroxyalkyl groups (e.g. hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl), alkoxyalkyl (e.g. methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, ethoxymethyl, 2-ethoxyethyl), cyanoalkyl (e.g. cyanomethyl, 2-cyanoethyl), (alkylamino) alkyl (e.g. (Methylamino) methyl, 2- (methylamino) ethyl, (ethylamino) methyl), (Dialkylamino) alkyl (e.g. (dimethylamino) methyl, 2- (dimethylamino) ethyl), haloalkyl (e.g. fluoromethyl, chloromethyl, Bromomethyl) and aralkyl (e.g. benzyl and phenethyl).  

If R⁶ represents an unsubstituted aryl group, special ones are Examples include phenyl and naphthyl.

If R⁶ represents a substituted aryl group, substituents therefor the above as substituents for the alkyl group R⁶ called groups. The number of substituents for the Group can range from 1 to 3 and if there are multiple substituents located on the group, these can be the same or in everyone desired combination may be different, the position the substituents of the group are in no way limited.

X represents a group formed by condensation with the benzene ring in the above formula, which is a hydroxy group and a Group Y has an aromatic ring (e.g. naphthalene or anthracene), or a heterocyclic ring (e.g. indole, Carbazole, benzocarbazole, dibenzofuran) forms.

When X represents a group containing a substituted aromatic Ring or hetero ring forms, substituents for the Ring z. B. halogen atoms (z. B. fluorine, chlorine and bromine) and Alkyl groups, preferably alkyl groups with 1 to 18 carbon atoms (e.g. methyl, ethyl, propyl, butyl, dodecyl, octadecyl, Isopropyl, isobutyl). The number of substituents can be one or two and if two substituents are attached group, they can be the same or different.

R1 can be an alkyl group, preferably an alkyl group having 1-18 carbon atoms, or a phenyl group, each of these groups may be substituted or unsubstituted.

When R1 represents an unsubstituted alkyl group specific examples of this are methyl, ethyl, propyl, butyl, Pentyl, hexyl, dodecyl, octadecyl, isopropyl, isobutyl, isoamyl, Isohexyl, neopentyl and tert-butyl.

When R¹ represents a substituted alkyl group, substituents can be therefor hydroxyl groups, alkoxy groups with 1 to 18 carbon atoms,  Cyano groups, amino groups, alkylamino groups with 1 to 18 carbon atoms, dialkylamino groups, with 2 alkyl groups, each of which has 1 to 18 carbon atoms, Halogen atoms and aryl groups with 6 to 15 carbon atoms be. Examples of substituted alkyl groups can be mentioned hydroxyalkyl groups (e.g. hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl), alkoxyalkyl groups (e.g. methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, ethoxymethyl, 2-ethoxyethyl), cyanoalkyl groups (e.g. cyanomethyl, 2-cyanoethyl), aminoalkyl groups (e.g. aminomethyl, 2-aminoethyl, 3-aminopropyl), (alkylamino) alkyl groups (e.g. (methyl amino) methyl, 2- (methylamino) ethyl, (ethylamino) methyl), (Dialkylamino) alkyl groups (e.g. (dimethylamino) methyl, 2- (Dimethylamino) ethyl), haloalkyl groups (e.g. fluoromethyl, Chloromethyl, bromomethyl) and aralkyl groups (e.g. benzyl, Phenethyl).

When R 1 represents a substituted phenyl group, examples are for substituents hydroxyl groups, alkoxy groups with 1 up to 18 carbon atoms, cyano groups, amino groups, alkyl amino groups with 1 to 18 carbon atoms, dialkylamino groups with 2 alkyl groups, each of which has 1 to 18 carbon atoms has, halogen atoms, alkyl groups with 1 to 18 carbon atoms and nitro groups. As examples of substituted Phenyl groups can be mentioned hydroxyphenyl, Alkoxyphenyl (e.g. methoxyphenyl, ethoxyphenyl, cyanophenyl, Aminophenyl, (alkylamino) phenyl (e.g. (methylamino) phenyl, (Ethylamino) phenyl), (dialkylamino) phenyl (e.g. (dimethyl amino) phenyl), halophenyl (e.g. fluorophenyl, chlorophenyl, Bromophenyl), alkylphenyl (e.g. tolyl, ethylphenyl, cumolyl, Xylyl, mesityl), nitrophenyl, and phenyl groups with two or three substituents (which can be the same or different).

The position of the substituent and the mutual relationship of positions for several substituents are in the substituted Phenyl group not limited.  

R² stands for hydrogen, alkyl, preferably alkyl with 1 to 18 carbon atoms, carbamoyl, carboxyl, alkoxycarbonyl, preferably alkoxycarbonyl with alkoxy groups having 1 to 18 Carbon atoms, aryloxycarbonyl, preferably aryloxycarbonyl with aryloxy groups having 6 to 20 carbon atoms, or a substituted or unsubstituted amino group.

When R² represents a substituted amino group, special ones are Examples include: B. methylamino, ethylamino, propylamino, Phenylamino, tolylamino, benzylamino, phenethylamino, dimethylamino, Diethylamino and diphenylamino.

When R² represents an alkyl group, specific examples are for this methyl, ethyl, propyl, butyl, dodecyl, octadecyl, isopropyl and isobutyl.

When R² represents an alkoxycarbonyl group, special ones are Examples include methoxycarbonyl, ethoxycarbonyl, propoxy carbonyl, butoxycarbonyl, isopropoxycarbonyl and benzyloxycar bonyl.

When R² represents an aryloxycarbonyl group, special ones are Examples include phenoxycarbonyl and tolyloxycarbonyl.

R³ represents an alkyl group, preferably an alkyl group with 1 to 20 carbon atoms, an aromatic group (e.g. phenyl, naphthyl), a heteroaromatic group, preferably a heteroaromatic group with 1 or more heteroatoms, selected from oxygen, nitrogen and / or sulfur (e.g. dibenzofuranyl, carbazolyl, benzocarbazolyl), or one substituted form of the groups just mentioned.

If R³ is a substituted or unsubstituted alkyl group stands, are specific examples of this in the context above substituted and unsubstituted alkyl mentioned with R¹ groups.  

When R³ represents a substituted aromatic group, e.g. B. a substituted phenyl group or a substituted naphthyl group, or substituted ones containing a hetero atom heteroaromatic group, such as. B. a substituted dibenzofuranyl group or a substituted carbazolyl group stands, can be mentioned as examples of substituents Hydroxyl groups, cyano groups, nitro groups, halogen atoms (e.g. fluorine, chlorine, bromine), alkyl groups with 1 to 18 carbon atoms (e.g. methyl, ethyl, propyl, dodecyl, Octadecyl, isopropyl), alkoxy groups with 1 to 18 carbon atoms (e.g. methoxy, ethoxy, propoxy, butoxy, pentyloxy, Isopropoxy, isobutoxy, isoamyloxy, tert-butoxy, neopentyloxy), Amino groups, alkylamino groups with 1 to 18 carbon atoms (e.g. methylamino, ethylamino, propylamino), dialkylamino groups with alkyl groups, each having 1 to 18 carbon atoms (e.g. dimethylamino, diethylamino, N-methyl-N-ethyl amino), arylamino groups with 6 to 12 carbon atoms (e.g. Phenylamino, tolylamino), diarylamino groups with two aryl groups, each having 6 to 15 carbon atoms (e.g. Di phenylamino), carboxyl groups, alkali metal carboxylato groups (Examples of the alkali metal cation are Na⁺, K⁺ and Li⁺) Alka limetallsulfonato groups (examples of the alkali metal cation are Na⁺, K⁺ and Li⁺), alkylcarbonyl groups (e.g. acetyl, propionyl, Benzylcarbonyl), arylcarbonyl groups with aryl groups, the Have 6 to 12 carbon atoms (e.g. benzoyl, toluoyl), Alkylthio groups with 1 to 18 carbon atoms (e.g. methylthio, Ethylthio), perfluoroalkyl groups having 1 to 18 carbon atoms (e.g. trifluoromethyl, trifluoroethyl) and arylthio groups with 1 to 18 carbon atoms (e.g. phenylthio, tolylthio). The number of substituents is from 1 to 3. If more than one Substituents are present on a group, these can be the same or different in any combination, the position of the substituents is not restricted.

R⁴ and R⁵ independently represent hydrogen or the same groups described for R³ above with the proviso that R⁴ and R⁵ are not both water at the same time  can be atoms.

B¹ and B² independently represent hydrogen, Halogen (e.g. chlorine, bromine, or iodine), alkyl, preferably alkyl with 1 to 18 carbon atoms, alkoxy, preferably alkoxy with 1 to 18 carbon atoms or substituted forms of the groups just mentioned.

When B¹ and B² are each substituted or unsubstituted Representing alkyl or alkoxy group are specific examples for the alkyl unit those substituted or unsubstituted Alkyl groups that have been mentioned in connection with R⁶.

The number of B¹ or B² that is a substituent on the benzene ring can be 1 to 4.

If A for

stands, the unity

in any of the 3 to 8 positions of the naphthalene ring, preferably in the 8 position.

W stands for a divalent group that has an aromatic Hydrocarbon forms, or a divalent group, the forms a hetero ring that contains one or more nitrogen atoms contains in the ring, the ring being substituted or unsubstituted can be.  

If the rings are substituted, examples of substituents Alkyl groups, halogen atoms, nitro groups, or hydroxyl groups. Examples of aromatic hydrocarbons by divalent Groups are formed are o-phenylene, p-naphthylene, peri-naphthylene, 1,2-anthraquinonylene and 9,10-phenanthrylene. As examples of heterocyclic groups with 1 or more nitrogen atoms in the ring by the divalent Group can be formed, 3,4-pyrazole diyl, 2,3- Pyridiyl, 4,5-pyrimidine diyl, 6,7-indazole diyl, 5,6-benzimidazole be called diyl and 6,7-quinoline diyl.

L represents hydrogen, alkyl, aryl or substituted Forms of these groups.

When L represents an alkyl group, it is preferably one Alkyl group with 1 to 17 carbon atoms. Specific examples for such groups are methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 3-heptyl, dodecyl and hepta decyl.

When L represents an aryl group, there are specific examples Phenyl and naphthyl.

When L is a substituted alkyl group or a substituted one Aryl group, can be mentioned as substituents Hydroxyl groups, alkoxy groups with 1 to 18 carbon atoms, Cyano groups, alkylamino groups with 1 to 18 carbon atoms, Dialkylamino groups with 2 alkyl groups, each with 1 to 18 carbons atoms, halogen atoms and aryl groups with 6 to 15 carbon atoms. Specific examples of substituted alkyl groups are hydroxyalkyl (e.g. hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl), alkoxyalkyl groups, (e.g. methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, ethoxyethyl, 2-ethoxyethyl), Cyanoalkyl groups (e.g. cyanomethyl, 2-cyanoethyl), (Alkylamino) alkyl groups (e.g. (methylamino) methyl, 2- (methyl amino) ethyl, (ethylamino) methyl), (dialkylamino) alkyl groups  (e.g. (dimethylamino) methyl, 2- (dimethylamino) ethyl), haloalkyl groups (e.g. fluoromethyl, chloromethyl, bromomethyl) and aralkyl groups (e.g. benzyl, phenethyl).

The number of substituents on the alkyl or aryl group can be 1 to 3. If there are multiple substituents on the group , they can be the same or in any one Combination may be different. The position of the substituents is not limited.

The bisazo compounds for use in the present invention are specifically illustrated below, but the Examples of concrete connections listed below are intended not as a limitation on the scope of the present invention be understood; e.g. B. are specific examples of the bisazo compound those represented by the following formulas (2) to (4) are shown, in which A₁ in Tables I, II and III represented groups and L₁ the groups shown in Table IV.  

Table I

Table III

Table IV

The new bisazo compounds for use in the present Invention can easily be made by conventional methods will. For example, the bisazo compounds of the formulas (2), (3) and (4) above by the one described below Processes are made.

A compound of the following formula (5), in which R⁷ is a hydrogen atom is available with nitric acid under suitable Conditions nitrided, e.g. B. in concentrated sulfuric acid, to give a compound of formula (5) in which R⁷ represents a nitro group. Thereupon the resulting Connection under suitable conditions e.g. B. with iron powder and dilute hydrochloric acid or with tin (II) chloride and Hydrochloric acid reduced to provide a compound of formula (5) in which R⁷ stands for -NH₂. Thereupon the connection diazotized and then with the corresponding coupling component (e.g. Naphthol AS) coupled, which creates the desired Bisazo compound of formula (2), (3) or (4) with ease can be obtained

in which Z stands for 0, S or NH.

Compounds of formula 5 in which R⁷ is hydrogen and Z stands for oxygen, can be produced with ease according to the procedure described in A.O. Fitton and R.K. Samalley, Practical Heterocyclic Chemistry (Academic Press, London and New York, 1968), p. 33. The connections, in which R⁷ is hydrogen and Z is sulfur, can are produced according to the method that in J. Heinze  and H. Baumgärtel, Chem. Ber., 103, 1572 (1970) is. The compounds in which R⁷ is hydrogen and Z is nitrogen can be manufactured according to the method that in G. M. Badger, The Chemistry of Heterocyclic Compounds, (Academic Press, New York and London, 1961), p. 190 is.

The following is an example of the production of some typical ones Compounds of formula (2) illustrated. The others Connections can be made by the same method will.

Production Example 1 Preparation of the bisazo compound of formula (2) in which A₁ the number A₁-41 and L₁ has the number L₁-8

42.4 g (0.2 mol) of benzoin and 27.3 g (0.2 mol) of caproyl chloride were dissolved in 250 ml of acetone and 17.4 g (0.22 mol) of pyridine were added dropwise with ice cooling and stirring. After a three hour reaction, the reaction mixture added to 1 liter of water and the crystalline crude product, the precipitated, was separated by filtration and from 400 ml of ethanol recrystallized, whereby 50.2 g of caproic acid ester of Received benzoin. Yield: 81%.

46.8 g (0.15 mol) of the ester thus obtained and 92.4 g (1.2 mol) Ammonium acetate were dissolved in 500 ml of acetic acid and under Reflux heated for 2 hours. Then 1 liter of water became Resulting reaction mixture given, which then with Ethyl acetate was extracted. The resulting extract was dried with Na₂SO₄ and then concentrated to give 39.41 g an oily crude product from 2-n-pentyl-4,5-diphenyloxazole received.

The next step was 14.55 g (0.05 mol) of the oily crude product mixed with 100 ml concentrated sulfuric acid and  11.12 g (0.11 mol) of potassium nitrate was added during the reaction system was kept at -5 to -10 ° C. After finishing The entire mixture was added for a further 2 hours continuously stirred and the temperature of the reaction system was raised to room temperature. Thereupon the reaction mixture poured into 1 liter of water and the precipitate formed was separated by filtration and from a mixed Solvent recrystallized from ethanol (600 ml) / acetone (120 ml). 14.12 g of a yellow flaky crystalline product from 2-n-pentyl-4,5-bis (p-nitrophenyl) oxazole were thus obtained. Yield: 74%.

7.62 g (0.02 mol) of the crystalline product thus obtained were dissolved in 250 ml dimethylformamide and 10.1 g reduced Iron, 16 ml of water and 6 ml of concentrated hydrochloric acid were added added in this order and the reaction mixture was heated to 100 ° C with stirring. Then the whole mixture stirred continuously for a further 5 hours. After completion of the implementation the reaction mixture was saturated with an aqueous Neutralized sodium carbonate solution. The one so neutralized Mixture of filtered mother liquor became 500 ml of water added and then extracted with ethyl acetate. The resulting one Extract was concentrated and then by silica gel column chromatography (Eluent ethyl acetate / hexane, 1: 1) cleaned, whereby 6.42 g of a waxy solid from 2-n-pentyl 4,5-bis (p-aminophenyl) oxazole. Yield: 83%.

481.5 mg (1.5 mmol) of the solid was mixed with 10 ml of N hydrochloric acid and 27.7 mg (3.3 mmol) of sodium nitrite were added. After stirring for 15 minutes, the diazonium solution formed was added to a solution containing 1.10 g (3 mmol) of a coupler component ((A₁-41) -H) dissolved in 20 ml of pyridine, and cooled with ice and the resulting one Solution was stirred continuously for 2 hours. The reaction mixture was poured into 200 ml of water, and the crystalline crude product formed was separated by filtration and then washed repeatedly with acetone (100 ml, 4 times). This gave 1.1374 g of the title compound in the form of a black-brown solid.
Decomposition point: 300 ° C or higher.

Elemental analysis (C₅₆H₃₉O₅F₆Cl₂):
Molecular weight: 1074.88
calc .: C 62.58%, H 3.66%, N 9.12%;
Found: C 62.37%, H 3.52%, N 9.02%.

Absorption spectrum in the visible:
Maximum absorption wavelength: 527 nm (in dimethylformamide with 5% ethylenediamine).

Production Example 2 Preparation of the bisazo compound of the formulas (2) in which A₁ has the number A₁-21 and L₁ has the number L₁-8

A coupling component ((A₁-21) -H) was used in place of the coupling component in Production Example 1, and the title compound was obtained in the form of a black solid.
Decomposition point: 300 ° C or higher.

Elemental analysis (C₆₈H₅₃O₇N₉):
Molecular weight: 1108.24
calc .: C 73.70%, H 4.82%, N 11.37%;
Found: C 73.65%, H 4.71%, N 11.30%.

Absorption spectrum in the visible:
Maximum absorption wavelength: 573 nm (in dimethylformamide with 5% ethylenediamine).

The other bisazo compounds can be made in the same way and Way as in the manufacturing examples described above are obtained, except that the coupling component and the corresponding Diazonium salt can be varied.

The electrophotographic photoreceptor of the present invention exhibits a photosensitive electrophotographic Layer on top of one or more bisazo compounds of the above  Formula included. They are electrophotographic photoreceptors of various types known and any of the known types can be used for electrophotographic Photoreceptor of the present invention can be used. Preferably the photoreceptor of the present invention has one of the following structure types:

• (I) A photosensitive electrophotographic layer which is a particular bisazo compound in a binder or a charge carrier transporting medium has, is on an electrically conductive Layer support applied.
• (II) A charge-generating layer that mainly is built up from the particular bisazo compound provided on an electrically conductive substrate and a layer of a charge carrier transporting Medium is over the charge-generating layer arranged.

The bisazo compound of the present invention acts as a photoconductive Substance and when this compound absorbs light, can generate a charge carrier with extremely high efficiency will. The charge carrier generated in this way can be via the bisazo compound be transported as a transport medium, however more effectively via a load transporting connection transported as a transport medium.

To form the electrophotographic photoreceptor from Type (I) are fine grains of the bisazo compound of the present Invention in a binder solution or in a solution, which a charge carrier transporting connection and contains a binder, dispersed and the resulting dispersion can be applied to an electrically conductive substrate and be dried. The thickness of the photosensitive formed electrophotographic layer is preferably in the range from 3 to 30 μm, in particular in the range from 5 to 20 µm.  

To form the electrophotographic photoreceptor from Type (II) is the bisazo compound according to the invention on a electrically conductive substrates by vacuum evaporation Plating applied or a solution of the compound, dissolved in a solvent such as B. an amine is on applied the substrate or a dispersion of fine Granules of the compound dispersed in a suitable solvent, optionally containing a binder dissolved therein, is applied to the substrate; and after the Drying the layer so applied becomes a solution that a charge carrier transporting compound and a binder contains, arranged over the layer and dried. The thickness of the layer containing the bisazo compound, the is a charge carrier generating layer, is preferably in the range of 0.01 to 4 µm and is in particular 2 µm or below. The thickness of the layer of charge transport Medium is preferably in the range of 3 to 30 µm, especially in the range of 5 to 20 µm.

The to form the photoreceptors of types (I) and (II) too Bisazo compound used is in the form of fine Grains with a grain size of 5 microns or less, preferably 2 µm or less, ground in a ball mill, sand mill, Vibration mill or a similar dispersion device, in front.

When forming the electrophotographic photoreceptor from Type (I) sensitivity is poor when the amount of Bisazo compound used is too low, but if this The amount is too large, the charging characteristic is bad and that The strength of the photosensitive layer formed is low. Accordingly, the proportion of the bisazo compound is in the photosensitive electrophotographic layer preferably in the range of 0.01 to 2 times, especially 0.05 up to 1 times the weight of the binder. The share of La Manure-transporting connection, if this exists  is preferably in the range of 0.1 to 2 times, in particular 0.3 to 1.3 times the weight of the binder. If the charge carrier transporting used The compound also acts as a binder, depending on the amount of Bisazo compound to be added preferably in the range of 0.01 up to 0.5 times the weight of the binder.

In the formation of the bisazo compound-containing layer, which is a charge carrier generating layer for the purpose of production the type (II) electrophotographic photoreceptor the amount of the bisazo compound is preferably in the range 0.1 to 20 times the weight of the binder. If the resulting layer has none sufficient sensitivity to light. The proportion of load carriers transporting connection in the charge carrier transporting Medium is preferably in the range of 0.2 to 2 times, in particular 0.3 to 1.3 times the weight of the Binder in the medium. If a carrier-transporting high molecular compound that also acts as a binder, any other binder is not used conducive.

In the formation of the electrophotographic photoreceptor In the present invention, additives such as. B. plasticizers or sensitizer, along with the binder be used.

The electrically conductive substrate for use in electrophotographic photoreceptor of the present invention can be a metal plate such. B. an aluminum, copper or zinc plate, a plastic sheet or film, e.g. B. a polyester sheet or film, by vacuum evaporation plating or dispersion coating with an electrically conductive Material (e.g. iridium oxide, SnO₂) coated, or a paper be processed in such a way that it is electrically conductive is.  

It is preferred to use an electrically insulating binder and to use film-forming, high molecular weight polymer, which is hydrophobic and has a high dielectric constant having. Examples of suitable high molecular weight polymers are listed below, of course are not to be interpreted as restrictive.

Polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, Polyvinylidene chloride, polystyrene, polyvinyl acetate, Styrene-butadiene copolymer, vinylidene chloride-acrylonitrile-Co polymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride Vinyl acetate-maleic anhydride copolymer, silicone resin, Silicone alkyd resin, poly-N-vinyl carbazole.

These binders are used individually or in the form of a mixture used by two or more.

As plasticizers such. B. mention biphenyl, biphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate, dimethylene glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, Polystyrene, dilauryl thiodipropionate, 3,5-dinitrosalicylic acid and various fluorocarbons.

In addition, a silicone oil or the like can be added to the surface properties of the electrophotographic To improve photoreceptor.

As a sensitizer such. B. mention chloranil, Tetracyanoethylene, methyl violet, rhodamine B, cyanine dyes, merocyanine dyes, pyrylium dyes and Thiapyrylium dyes.

Carrier-transporting connections are generally divided into two groups, namely electron-transporting Connections and positive hole transport connections. Both groups can be electro in the invention  find photographic photoreceptor use. The electrons transporting compounds are electron-attracting Group-containing compounds, such as. B. 2,4,7-trinitro 9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 9-dicyano methylene-2,4,7-trinitrofluorenone, 9-dicyanomethylene-2,4,5,7- tetranitrofluorenone, tetranitrocarbazole-chloranil, 2,3-dichloro- 5,6-dicyanobenzoquinone, 2,4,7-trinitro-9,10-phenanthrenequinone, Tetrachlorophthalic anhydride, tetracyanoethylene and Tetracyanoquinodimethane.

The positive hole transporting compounds are electron donating group containing compounds. Examples of this are given below.
High molecular weight compounds:

• (1) Polyvinyl carbazole and derivatives thereof, described in JP-B-34-10 966.
• (2) vinyl polymers (e.g. polyvinylpyrene, polyvinylanthracene, Poly-2-vinyl-4- (4'-dimethylaminophenyl) -5-phenyloxazole, Poly-3-vinyl-N-ethylcarbazole) described in JP-B-43-18 674 and JP-B-43-19 192.
• (3) Polymers (e.g. polyacenaphthylene, polyinden, acenaphthylene / styrene Copolymer) described in JP-B-43-19 193.
• (4) Condensed resins (e.g. pyrene-formaldehyde resin, bromine pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin), described in JP-B-56-13 940.
• (5) Various triphenylmethane polymers described in JP-A- 56-90 883 and JP-A-56-1 61 550.

Low molecular weight compounds:

• (6) Triazole derivatives described in U.S. Patent 31,127.
• (7) Oxadiazole derivatives described in U.S. Patent 3,189,447.
• (8) Imidazole derivatives described in JP-B-37-16 096.
• (9) polyarylalkane derivatives described in U.S. Patent 3,615,402; 38 20 989 and 35 42 544, JP-B-45-555, JP-B-51-10 983, JP-A-51-93 224, JP-A-55-1 08 667, JP-A-55-1 56 953 and JP-A-56-36 656.  
• (10) pyrazoline derivatives and pyrazolone derivatives described in US-PS 31 80 729 and 42 78 746, JP-A-55-88 064, JP-A-55-88 065, JP-A-49-1 05 537, JP-A-55-51 086, JP-A-56-80 051, JP-A-56-88 141, JP-A-57-45 545, JP-A-54-1 12 637 and JP-A-55-74 546.
• (11) phenylenediamine derivatives described in U.S. Patent 3,615,404; JP-B-51-10 105, JP-A-54-83 445, JP-A-54-1 10 836, JP-A-54-1 19 925, JP-B-46-3 712 and JP-B-47-28 336.
• (12) arylamine derivatives described in U.S. Patent 3,567,450, JP-B-49-35 702, DE-AS-11 10 518, US-PS 31 80 703, 32 40 597, 36 58 520, 42 32 103, 41 75 961 and 40 12 376, JP-A-55-1 44 250, JP-A-56-1 19 132, JP-B-39-27 577 and JP-A-56-22 437.
• (13) Amino substituted chalcones described in U.S. Patent 35 26 501.
• (14) N, N-Bicarbazyl derivatives described in U.S. Patent 3,542,546.
• (15) Oxazole derivatives, described in U.S. Patent 3,257,203.
• (16) Styrylanthracene derivatives described in JP-A-56-46 234.
• (17) Fluorenone derivatives described in JP-A-54-1 10 837.
• (18) hydrazone derivatives described in U.S. Patent 3,717,462, JP-A-54-59 143 (corresponding to US-PS 41 50 987), JP-A-55-52 063, JP-A-55-52 064, JP-A-55-46 760, JP-A-55-85 495, JP-A-57-11 350, JP-A-57-1 48 749 and JP-A-57-1 04 144.
• (19) benzidine derivatives described in U.S. Patent 4,047,948; 40 47 949, 42 65 990, 42 73 846, 42 99 897 and 43 06 008.
• (20) stilbene derivatives described in JP-A-58-1 90 953, JP-A-59-95 540, JP-A-59-97 148, JP-A-59-1 95 658 and JP-A-62-36 674.

The charge-carrying connections for use in the present invention are not based on the above mentioned compounds (1) to (20) limited, but also other known charge carrier transporting connections can of course be used in the present invention Find.  

Two or more types of carrier-transporting Compounds can optionally be used together.

In the photoreceptor thus obtained according to the invention, optionally an adhesive layer or a barrier layer between the electrically conductive substrate and the photosensitive Layer can be provided. As materials used for Formation of the optional adhesive layer or barrier layer used can be, the above-mentioned polymers with high molecular weight, which are used as binders can be mentioned, as well as gelatin, casein, poly vinyl alcohol, ethyl cellulose, carboxymethyl cellulose, which in JP-A-59-84 247 describes vinylidene chloride polymer latex, which styrene-butadiene polymer latex described in JP-A-59-1 14 544 and alumina. The thickness of the layer is preferably at 1 µm or less.

As described in detail above, the invention is characterized electrophotographic photoreceptor that it has high sensitivity and outstanding durability shows.

The electrophotographic photoreceptor of the present invention can be used in various areas of electrophotographic Copiers and printers that use a laser beam or use a Braun tube as a light source, in large Scope used.

The bisazo compound-containing photoconductive according to the invention Layer in an imaging tube in a video camera or as a photoconductive layer in an image-receiving solid element, which is a light-absorbing layer (photoconductive layer) has on the entire surface a known one-dimensionally or two-dimensionally arranged Semiconductor circuit for transport or for  Scanning of signals is provided. In addition, the Composition can also be used as photoconductive Layer for a solar battery, as in A.K. Ghosh and Tom Feng, J. Appl. Phys., 49 (12) 5982 (1978).

Furthermore, the bisazo compound according to the invention can also be used are colored as photoconductive grains in one Photoelectrophoresis system or as colored grains in one dry or wet electrophotographic developer.

According to the disclosure in JP-B-37-17 162, JP-A-55-19 063, JP-A-55-1 61 250 and JP-A-57-1 47 656 can do the inventive Bisazo compound in the above-mentioned charge carrier-transporting Compound (e.g. oxadiazole derivatives, hydrazone derivatives) together with an alkali-soluble resin liquid (e.g. phenolic resin) and the resulting Dispersion can be applied to an electrically conductive substrate (e.g. aluminum) and dried. Then the layer support thus coated is exposed imagewise, developed with a toner and with an aqueous alkaline Solution etched around a printing plate with a high resolving power, high durability and high sensitivity to obtain. A printed one can be printed in the same way Circuit are manufactured.

The following examples are intended to illustrate the present invention Illustrate in more detail, but in no way limit it. Unless otherwise stated, parts mean Parts by weight. Unless otherwise stated, Cell percentages, ratios, etc. on a weight basis.

Example 1

Part of the bisazo compound of formula (2) in which A₁ the numbers A₁-21 and L₁ have the numbers L₁-8 (produced in the above Preparation example 1), 5 parts of 4,4'-bis (diethylamino) -2,2'-  dimethyltriphenylmethane and 5 parts polycarbonate of bisphenol A. were added to 95 parts of dichloromethane and under Production of a coating liquid in a ball mill ground and mixed. This liquid was applied to one transparent electrically conductive substrate (manufactured by applying an indium oxide film on the surface of a 100 µm thick polyethylene terephthalate film Vacuum evaporation plating and surface resistance of 10³ ohms) applied with a round wire rod and dried, making an electrophotographic Photoreceptor with a single layer electrophotographic photoconductive layer with a thickness of received about 8 µm.

To examine the electrophotographic Photoreceptor became an electrostatic copy tester (Type SP-428 manufactured by Kawaguchi Electric Co.) det.

In short, the photoreceptor was charged to +400 V by corona discharge (+5 kV) and irradiated with a tungsten lamp (color temperature 2854 K) so that the surface was 4 lux. The time required for the surface potential to drop to half the original surface potential was obtained, and the half-value exposure E ₅₀ (lux × sec) was calculated therefrom and was 6.3 lux × sec.

Examples 2-10

The procedure of Example 1 was repeated except that that the bisazo compound shown in Table 5 below instead of the bisazo compound prepared in Preparation Example 1 has been used. So different single-layered ones electrophotographic photoreceptors manufactured and these were tested in the same manner as in Example 1.  

The half-value exposure E ₅₀ by positive charging was determined in each sample. The results obtained are shown in Table V.

Table V

Example 11

5 parts of the bisazo compound of formula (2) in which A₁ the number C₁-21 and L₁ has the number L₁-8, (produced in Production example 1) above were carried out in a solution 5 parts of polyester resin (trademark Vilon®20, manufactured from Toyobo Co., Ltd.) dissolved in 50 parts of tetrahydrofuran, dispersed by milling in a ball mill for 20 hours and the resulting dispersion was made electrical conductive layer support (produced by applying a  Aluminum layer on the surface of a 75 µm thick Polyethylene terephthalate film by vacuum evaporation plating and an electrical resistance on the surface of 4 × 10² ohms) with a round wire rod applied and to form a 0.5 µm thick charge-generating Layer dried.

A solution of 3.6 parts of p- (diphenylamino) - benzaldehyde-N'-methyl-N'-phenylhydrazone by the following Formula is represented:

and 4 parts of bisphenol A polycarbonate dissolved in 11.3 parts Dichloromethane and 26.6 parts of 1,2-dichloroethane and with a round wire rod is applied to the charge-generating layer and to form an 11 µm thick charge-transporting Layer dried. So became an electrophotographic Photoreceptor with a two-layer photosensitive Layer.

The photoreceptor was then charged by corona discharge (-6 kV) and the initial surface potential was indicated by V ₀. Then, the photoreceptor was irradiated with a tungsten lamp so that the light intensity on the surface was 30 lux, and the exposure (E ₅₀) necessary to cause the surface potential to drop to half the original surface potential V ₀ became measured. The surface potential (residual potential V _R ) was also determined after exposure to 60 lux × sec.

The same measurement was carried out after 3000 repetitions. The results obtained are in Table VI below shown.

Table VI

Examples 12-20

The procedure of Example 11 was repeated, except that the bisazo compounds shown in Table VII below were used in place of the bisazo compound of Example 11. Various two-layer electrophotographic photoreceptors were prepared and tested in the same manner as in Example 11. The half-value exposure E ₅₀ was measured for each sample. The results are shown in Table VII.

Table VII

Example 21

5 parts of the bisazo compound of formula (2) in which A₁ the number A₁-21 and L₁ has the number L₁-8 (manufactured in Production Example 1), 40 parts of those used in Example 11 Hydrazone compound and 100 parts of a benzyl meth acrylate-methacrylic acid copolymers ([η] = 0.12 at 30 ° C in Methyl ethyl ketone, methacrylic acid content: 32.9%) were added Given 660 parts of dichloromethane and disper with ultrasound yaws.

The resulting dispersion was made to a thickness of 0.25 mm a sandblasted aluminum plate and dried, thereby making a photosensitive electrophotographic Printing plate material with a light  sensitive electrophotographic layer of a dry thickness of 6 µm.

The sample was charged by corona discharge (+6 kV) in the dark so that the surface potential of the photosensitive layer was approximately +600 V. The surface of the sample was then irradiated with a light intensity of 2.0 lux using a tungsten lamp (color temperature 2854 K); whereupon the half-value exposure E ₅₀ was determined to be 6.2 lux × sec.

The sample was then placed on a surface in the dark potential of approximately +400 V and then charged by a attached to it, showing a transferable positive image Originally exposed image-wise. The sample so exposed was immersed in a liquid developer containing a Contained toner made by making 5 parts fine Polymethyl methacrylate grains (toner) and 0.01 part soybeans lecithin to 1000 parts of Isoper®H (petroleum solvent, manufactured by Esso Standard Company), giving a sharp edge positive toner image was obtained.

Thereupon was 30 seconds to fix the toner image heated to 100 ° C. The printing plate material thus produced was in a 70 part solution for about 1 minute Sodium metasilicate hydrate, dissolved in 140 parts of glycerol, 550 parts of ethylene glycol and 150 parts of ethanol immersed and then by gently brushing the surface with flowing Washed water, causing the photosensitive layer to that had no toner attached was removed. So became a printing plate receive.

Instead of the liquid developer, it became electrostatic latent image by magnetic brush development with Xerox 3500 toner (manufactured by Fuji Xerox Co., Ltd.) developed and then heated to 80 ° C for 30 seconds for fixation. Then the photosensitive layer was used without toner  removes an alkaline solution, creating a printing plate was obtained.

The printing plate thus produced was placed in a Hamada Star 600 CD offset press was given and the printing process was started done in the usual way. 50,000 prints that all were extremely sharp and had no background stains, could be preserved.

Having described the invention in detail with reference to specific embodiments thereof have been described, it is obvious to a person skilled in the art that the most varied Changes and modifications can be made without departing from the scope of the present invention.

Claims (17)

1. Photoconductive composition, characterized in that it comprises at least one bis azo compound, which is represented by the following general formula (I): in which Z for stands where
R⁶ represents a hydrogen atom or a substituted or unsubstituted alkyl or aryl group;
A for stands;
B₁ and B₂, which may be the same or different, independently represent hydrogen, halogen or a substituted or unsubstituted alkyl or alkoxy group;
X represents a group which forms a substituted or unsubstituted aromatic or heterocyclic ring by condensation with the benzene ring in the above formula having a hydroxy group and a group Y on the ring;
Y for stands;
R¹ represents a substituted or unsubstituted alkyl or phenyl group;
R² represents hydrogen, an alkyl group, a carbamoyl group, a carboxyl group, an alkoxycarbonyl group, an aryl oxycarbonyl group or a substituted or unsubstituted amino group;
R³ represents an alkyl group, an aromatic group or a heteroaromatic group, which groups may be substituted or unsubstituted;
R⁴ and R⁵ independently of one another are hydrogen, an alkyl group, an aromatic group or a heteroaromatic group, these groups being able to be substituted or unsubstituted, with the proviso that R⁴ and R⁵ cannot both be hydrogen at the same time and that if Y is R⁵ cannot be hydrogen,
W represents a divalent group that forms an aromatic hydrocarbon ring or represents a divalent group that forms a hetero ring that contains one or more nitrogen atoms in the ring, which rings may be unsubstituted or substituted; and
L represents a substituted or unsubstituted alkyl or aryl group. 2. Composition according to claim 1, characterized in that the aromatic represented by R³, R⁴ and R⁵ Groups are phenyl or naphthyl groups and that the heteroaromatic represented by R³, R⁴ and R⁵ Groups are heteroaromatic groups that have one or more Heteroatoms selected from oxygen, nitrogen and / or Have sulfur. 3. A composition according to any one of claims 1 or 2, characterized in that the divalent represented by W. Group containing an aromatic hydrocarbon forms an o-phenylene group, o-naphthylene group, peri- Naphtylene group, 1,2-anthraquinolene group or 9,10-phen anthyrylene group and that represented by W. divalent group that forms a hetero ring, one 3,4-pyrazole diyl group, 2,3-pyridiyl group, 4,5-pyrimidine diyl group, 6,7-indazole diyl group, 5,6-benzimidazole diyl group or 6,7-quinoline diyl group. 4. A composition according to any one of claims 1 to 3, characterized in that the alkyl represented by L.  group is an alkyl group of 1 to 17 carbon atoms and that the aryl group represented by L is a Is phenyl or naphthyl group. 5. Electrophotographic photoreceptor, characterized in that it has a layer that has a charge carrier-transporting connection and a load carrier generating connection on an electrically conductive Contains layer carriers, the charge carrier-generating A bisazo compound according to any one of claims 1 to 4. 6. Electrophotographic photoreceptor, characterized in that he is a carrier transporting Compound containing layer and a charge layer containing carrier-producing compound on one comprises electrically conductive support, the Charge generating compound a bisazo compound according to one of claims 1 to 4. 7. Photoreceptor according to claim 5, characterized in that the layer also comprises a binder. 8. Photoreceptor according to claim 6, characterized in that the containing a charge-generating connection Layer containing the bisazo compound as the main component and that the charge carrier transporting connection containing layer on this a charge carrier-generating Connection containing layer is provided. 9. Photoreceptor according to claim 5, characterized in that the layer has a thickness of 3 to 30 microns. 10. Photoreceptor according to claim 9, characterized in that the layer has a thickness of 5 to 20 microns.   11. Photoreceptor according to claim 8, characterized in that that containing a charge-generating compound Layer has a thickness of 0.01 to 4 microns and that the charge carrier transporting connection containing layer has a thickness of 3 to 30 microns. 12. Photoreceptor according to claim 11, characterized in that that containing a charge-generating compound Layer has a thickness of 0.01 to 4 microns and that the charge carrier transporting connection containing layer has a thickness of 5 to 20 microns. 13. Photoreceptor according to claim 5, characterized in that that the layer also contains a binder that the Bisazo compound in this layer in an amount that corresponds to 0.01 to 2 times the weight of the binder, is present and that the charge carrier-transporting Compound in this layer in a lot is present, which is 0.1 to 2 times the weight of Binder corresponds. 14. Photoreceptor according to claim 13, characterized in that the bisazo compound in this layer in an amount is present, which is 0.05 to 1 times the weight of the Binder corresponds and that the charge carrier-transporting Compound in this layer in a lot is present, which is 0.3 to 1.3 times the weight of Binder corresponds. 15. Photoreceptor according to claim 5, characterized in that the bisazo compound is present in the layer in an amount which is 0.01 to 0.5 times the weight of the Carrier-transporting connection corresponds. 16. Photoreceptor according to claim 6, characterized in that contains a charge-generating connection  layer also contains a binder, the Amount of the bisazo compound 0.1 to 20 times the weight of the binder, and that the one charge carrier layer containing transporting compound also contains a binder, the amount of Carrier-transporting connection the 0.2 to Corresponds to twice the weight of the binder. 17. Photoreceptor according to claim 16, characterized in that that the amount of bisazo compound in the one charge layer containing carrier-producing compound Corresponds to 0.1 to 20 times the weight of the binder and the amount of carriers transporting Connection in the connection carrying a charge carrier containing layer 0.3 to 1.3 times the Weight of the binder corresponds.